Vagal Stretch Receptor Signaling (2D)

This 2D schematic models the first step of gastric interoception: how vagal afferent nerve terminals (intraganglionic laminar endings, IGLEs) wrapped around the stomach wall convert mechanical stretch into an electrical signal the brain can read. As the modeled stomach fills, wall tension gates mechanosensitive channels, producing a graded receptor potential that is Hill-transformed into a rate-coded train of action potentials traveling up the vagus nerve toward the nucleus tractus solitarius in the brainstem. Adjust gastric fill and circulating CCK — the gut hormone that sensitizes these same fibers — switch between slowly-adapting (tonic fullness) and rapidly-adapting (phasic contraction) fiber behavior, tune conduction velocity, or sever the nerve to see why vagotomy silences the signal outright, all while live strip-chart traces plot the receptor potential and the spike train in real time.